#!/usr/bin/env python3

import sys

if __name__ == '__main__':
     

     alphabet = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','ñ','o','p','q','r','s','t','u','v','x','y','z']
     d = {}

     for word in sys.stdin:
        #Replaces
        w = word.lower()
        w = w.replace('\n','')
        w = w.replace('*','')
        w = w.replace('#','')
        w = w.replace('\\','')
        w = w.replace('n~','ñ')
        w = w.replace('$','')
        w = w.replace(' ','')

        #filter words
        f = False

        #filter bad characters
        for l in w:
            if l not in alphabet:
                f = True
       #         print( l)
                continue

            d[l]=l
        
        #len1
        if len(w) == 1:
            f = True

        if f:
           continue 
        
        print (w)
     k = d.keys() 
     print(k,file=sys.stderr)


